There are some organic compounds released from a specific source, which exert influence on human bodies in terms of general toxicity, carcinogenicity, and the like. In particular, toxic compounds used as chemical weapons are considerably detrimental with respect to human bodies. The environmental restoration from contamination by such toxic compounds becomes problematic. Conventionally, there have been the following methods for decontaminating such toxic compounds: a method in which a mixed gas of ozone and hydrogen peroxide is used (Patent Document 1); a method in which toxic compounds are decomposed by combustion and acidic poisonous gas generated is neutralized with an aqueous solution of sodium hydroxide (Patent Document 2); a method in which toxic compounds are subjected to aqueous solution of sodium hydroxide (Patent Document 2); a method in which toxic compounds are subjected to evaporative removal by heating in a heating furnace under an airtight condition (Patent Document 3); and a method in which toxic compounds are decomposed by releasing a decontamination reagent which contains a photocatalyst, and then irradiating light including ultraviolet rays (Patent Document 4).
However, the method of using ozone described in the cited Patent Document 1 has a problem in that since ozone is corrosive, a treatment apparatus considerably deteriorates and the maintenance thereof is complicated. In addition, Patent Documents 2 and 3 require a large-scale apparatus, which has a heating furnace for burning toxic compounds. Furthermore, the decomposed products obtained after burning toxic compounds are also harmful, and therefore a neutralizing step therefor is required. For this reason, the operation is complicated. On the other hand, Patent Document 4 provides a method of releasing a decontaminating reagent, which is simple, but has a problem in that the toxic compounds do not decompose without irradiating light containing ultraviolet rays, and the decomposition cannot occur in a dark place.